List Comprehensions | HackerRank

Goal

Print a list of all possible coordinates given by (i, j, k) on a 3D grid where the sum of i + j + k is not equal to n.

Solution

You can simply make a condition statement {(i + j + k) != n} to append all (i,j,k) combinations into list and print the list. 

There are two simple ways to solve this problem. You can use simply multiple loops, but you can use easily loop comprehensions. 

1) The for statement

# List Comprehensions

if __name__ == '__main__':
    x = int(input())
    y = int(input())
    z = int(input())
    n = int(input())

    results = []

    for i in range( x + 1):
        for j in range( y + 1):
            for k in range(z + 1):
                if (i + j + k) != n:
                    results.append([i, j, k])


    print(results)

2) List Comprehension

# List Comprehensions

if __name__ == '__main__':
    x = int(input())
    y = int(input())
    z = int(input())
    n = int(input())

    results = [[i,j,k] for i in range(x+1) for j in range(y+1) for k in range(z+1) if i+j+k != n]

    print(results)

Print Function | HackerRank

Goal

Print the list of integers from 1 through give n as a string, without spaces

Solution

To solve this problem, you can use for statement and str class to convert integer value to string object. 

# Print Function

if __name__ == '__main__':
    n = int(input())
    
    number = ""
    for i in range(1, n+1, 1):
        number += str(i)
        
    print(int(number))

Write a function | HackerRank

Goal

This task is to return true if a give year is a leap year, otherwise return false

Solution

There are three main conditions to check leap year:

1. It can be evenly divided by 4 - leap year

2. It can be evenly divided by 100, it is NOT a leap year, unless it is evenly disivible by 400 - leap year

3. Otherwise it is not a leap year.

These conditions can be shown in this code.

# Write a function

def is_leap(year):
    leap = False
    
    # Write your logic here
    if year % 4 == 0:
        if year % 100 == 0:
            if year % 400 == 0:
                leap = True
            else : 
                leap = False
        else:  
            leap = True
        
    else:
        leap = False
    
    return leap

year = int(input())
print(is_leap(year))